At present grips for tennis rackets, badminton rackets, bicycle handles, motorcycle handles, steering wheels of cars, hammers, jackhammers, etc., can be classified into two kinds. One kind is an elastic solid grip made of rubber or plastic, and the other is a hollow-sectioned grip made of rubber or plastic. The former, the solid grips, have no more than the elasticity of their material for absorbing shocks, and are thus without any additional structural benefits. So their elasticity is definite, not adjustable for various practical uses. The latter have the elasticity of the material plus that provided by a plurality of the hollow sections formed therein. So they can save more material and have better elasticity than the former. In spite of that, they still have drawbacks in that the elasticity of the material is still constant and the elasticity provided by the hollow sections is not changeable.
Those kinds of conventional grips can hardly satisfy a variety of shock-absorbing functions for different objects or tools in practical use.